I planted a small fittonia albivenis in a bioactive vivarium about a month ago (and have only just introduced my gecko to the tank last night, so he can be ruled out as the cause of the problem). Since I planted it, the leaves seem to consistently wilt and drop off, though the plant itself doesn't seem to be dying--the stems are still firm and green, and it continues to grow new leaves, many of which are still dropping off. I thought maybe it was shock, but it's been weeks--and I don't know enough about plants to know whether that's normal or not. The temperature in the vivarium is 70-75 degrees fahrenheit, the humidity averages around 60% (spikes up to 80-90% and dries down to 50%, but usually hovers around 60% the longest), and the soil is kept moist but drains well. I have two 13w Arcadia Jungle Dawn LED grow lights above the tank. I also have a fittonia verschaffeltii planted in there as well, under the same conditions, and it's thriving, which is why I just can't figure this one out. I do mist the tank, usually twice daily, and I wondered if maybe it doesn't like its leaves being wet--but again, this doesn't seem to bother the other fittonia. I've been trying to avoid misting it directly, at any rate, just in case. The only other thing I can think of worth mentioning is that it is partially shaded by the pilea nearby.

I found a couple other threads regarding fittonias, but the issue with those seemed to be more with a lack of humidity and the leaves yellowing before dropping, which mine aren't doing. Can anyone tell me what might be the problem, or what I can do to help it?

Hopefully these pictures are helpful, and I've included a picture of the other fittonia for comparison:

edited to add this photo of the bottom of the viv to give an idea of its surrounding conditions (bottom right, in between the pileas):

From my experience with Fittonias, all of them like shady places. I actually have both of these right now grown in my place and I will show you how they do, with just spraying and full shade. They don't like the light, so I am wondering if the LED you have on this one is causing the problem? The Verschaffeltii is always a harder plant than the albivenis, which is hard to keep. You can see that even though they were purchased the same time, the growth is not the same, it is somewhat of a slow grower. On the other hand, it is possible its roots, which are quite sensitive were disturbed during the placing in the terrarium and it responds this way. Was the water you used for spraying in room temperature? Oh, and I wanted to ask you, is it a closed environment/vivarium?

Here are mine, so you can see the growth difference between them.

In some Native languages the term for plants translates to "those who take care of us."
Robin Wall Kimmerer